Dear Mr. Taggart,
Thank you for posting your request on History Hub!
We searched online and located a blog post by Eric J. Mink that cites the following records: Record Group 156: Records of the Office of the Chief of Ordnance – “Summary Statements of Quarterly Returns of Ordnance and Ordnance Stores on Hand in Regular and Volunteer Army Organizations, 1862-1867, 1870-1876.” (Microcopy 1281, Rolls 1, 2 and 4). National Archives and Records Administration, Washington, D.C.
Microfilm Publication M1281 is available for viewing at the National Archives in Washington, DC. You can also order digital reproductions for a fee. For more information, please visit https://www.archives.gov/shop/ and click on "Request & Order Reproductions Online." Select "microfilm." Type in the microfilm publication M1281 and click on "search." A listing of the publication title(s) will appear. Click on the name of the publication. That will take you to a summary page. On the right hand side of the page will be a pdf file. Click on "View Important Publication Details." This is a listing of the contents of the microfilm rolls.
We also searched the National Archives Catalog and located 320 record series in the Records of the Office of the Chief of Ordnance (Record Group 156) that include records from the 1860s. To access these records, please contact the reference unit listed as the contact under the “Archived Copies” heading in the Catalog description.
For questions about whether any digital copies of records posted online by NPS Historian Eric J. Mink are still available online, please contact the Fredericksburg & Spotsylvania National Military Park, Virginia.
We hope this information is helpful. Best of luck with your research!
Thank you for the reply with this useful information.